<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <button onclick="alert('警告')"></button>
    <button onclick="confirm('您确定要删除吗')">弹出确认框</button>

    <script>
        console.log(parseInt(6.6))
        console.log(parseInt(6.1))
        console.log(parseInt(6))
        console.log(parseInt('hhh'))   //NaN
        console.log(parseFloat(6.6))
        console.log(parseFloat('2.3'))
        console.log(parseFloat('hhh'))  //NaN


        //判断是否为非数字
        console.log(isNaN('jhh'))  //true
        console.log(isNaN(1))


    </script>
</body>
</html>